メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.4875000 38.4500000, 141.4937500 38.4500000, 141.4937500 38.4541667, 141.4875000 38.4541667, 141.4875000 38.4500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral